In a vehicle such as an automobile, a luggage space is located on the rear side of a backrest of a rear seat, for example. In such a vehicle, there is a possibility that a piece of luggage in the luggage space moves to the vehicle front side at the time of a rear end collision and comes into contact with the backrest, and a large load is applied to the backrest.
JP 2002-52982 describes a vehicle rear structure in which a safety block extending in the vehicle-width direction is arranged between a backrest of a rear seat and a luggage space on the rear side of the backrest. The safety block is provided with a projecting portion that projects upward and extends over the vehicle-width direction, and a side end that is bent downward from an end of the projecting portion in the vehicle front-rear direction.
In JP 2002-52982, a closed section constituted by the safety block and a rear floor panel is formed by coupling a lower part of the side end of the safety block to an upper face of the rear floor panel that forms a vehicle floor, using a bolt or the like. Note that an auxiliary reinforcement material which projects downward is installed at a position overlapped by the safety block as viewed in the vehicle vertical direction, on a lower face of the rear floor panel.
JP 2002-52982 states that even if a piece of luggage moves to the vehicle front side at the time of a rear end collision or the like, the luggage is prevented from entering a passenger compartment by the projecting portion of the safety block.
In the structure described in JP 2002-52982, a situation may possibly occur in which, at the time of a rear end collision or the like, a piece of luggage gets over the projecting portion of the safety block and enters the passenger compartment, depending on the size of the piece of luggage. For this reason, as an example, a structure is conceivable in which a cross member is spanned in the vehicle-width direction on the vehicle rear side of the backrest and above the rear floor panel. Here, the cross member is arranged while inclining obliquely upward on the rear side so as to face the backrest.
However, with this structure, it is necessary, in order to withstand an impact load applied from the luggage, to attach the cross member to a vehicle body via a large bracket that is provided in the vehicle body and extends in the vehicle vertical direction. Consequently, this structure requires the large bracket, and a problem arises in that the weight and costs of the vehicle body increase.
Note that configurations are also conceivable in which members such as pipes spanned in the vehicle-width direction are attached to the vehicle body in a crossing manner on the rear side of the backrest, and in which the strength of the backrest itself is increased. However, both configurations increase the weight and costs of the vehicle body.
A configuration is also conceivable in which the cross member is directly joined to the vehicle body while not using a bracket. However, in this case, if the piece of luggage in the luggage space moves to the vehicle front side at the time of a rear end collision or the like, the piece of luggage first comes into contact with an upper edge of the cross member that inclines obliquely upward on the rear side. Then, there is a possibility that the load concentrates on the upper edge of the cross member, welding is peeled off in an upper part of a joint portion of the cross member and the vehicle body, and the cross member withdraws.
In view of the foregoing problems, an object of the present invention is to provide a vehicle rear structure capable of preventing a cross member arranged on the vehicle rear side of a backrest from withdrawing at the time of a rear end collision.